1. Field of the Invention
The present invention relates to substrate processing apparatus incorporating a lithographic apparatus and a device manufacturing method.
2. Related Art
A lithographic apparatus is a machine that applies a desired pattern onto a target portion of a substrate (e.g., a workpiece, an object, a display, etc.). The lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs), flat panel displays, and other devices involving fine structures. In a conventional lithographic apparatus, a patterning means, that is alternatively referred to as a mask or a reticle, can be used to generate a circuit pattern corresponding to an individual layer of the IC (or other device), and this pattern can be imaged onto a target portion (e.g., comprising part of a die, one die, or several dies) on a substrate (e.g., a silicon wafer or glass plate) that has a layer of radiation-sensitive material (e.g., resist). Instead of a mask, the patterning means can comprise an array of individually controllable elements that generate the circuit pattern. Lithographic systems utilizing such arrays are generally described as maskless systems.
In general, a single substrate will contain a network of adjacent target portions that are successively exposed. Known lithographic apparatus include steppers, in that each target portion is irradiated by exposing an entire pattern onto the target portion in one go, and scanners, in that each target portion is irradiated by scanning the pattern through the beam in a given direction (the “scanning” direction), while synchronously scanning the substrate parallel or anti-parallel to this direction.
It is known to batch process substrates, in the production of a wide variety of devices. For example, in the manufacture of flat panel displays (FPDs) it is known to use a mask-based exposure tool (i.e., a lithographic tool incorporating a fixed, non-programmable patterning device), and to carry out the exposure on a single substrate. Typically, a number of exposure steps are required, along with additional pre- and post-exposure processing steps to build up the FPD device structure, each step being carried out by a respective and separate processing tool. In each tool, the substrate is supported by a respective support stage, and batch processing has necessitated numerous handling steps, delivering the substrate to the series of support stages, collecting the substrate from each support stage after the respective processing step is complete, and transporting the substrate between the separate tools. This has meant that only approximately 65% of the Turn Around Cycle Time (TACT) for processing a substrate has been “useful” exposure time, the rest being time spent on transport, handling, and metrology. The use of separate tools and the need for complex handling systems for loading, unloading, and inter-tool transport have also required large fabrication facilities.
Therefore, what is needed is a system and method that obviate or mitigate the problems outlined above.